iPhone app locks briefly when set to sync on start

When I switch back to the Toodledo iPhone application from another application (like having made a call or looked at a website) there is a very noticeable pause as the application prepares to synchronize and the application does not respond to input.

If there is a network signal, once synchronization is in progress the application is responsive again - it's just the pause before this that is _incredibly_ annoying.

If there is no network available ie you are making a phone call, then switching back to the Toodledo iPhone application it hangs for some time before coming back to life. This is most annoying having launched a call from the hyperlinked phone number in a Todo note.